And that clearly makes you the Internet guru
From what I've been told by several different people, one being a working gunsmith, you can risk hitting the half cock catch. If you keep the trigger fully depressed you can avoid that but why would the sales guy assume the joe blow customer is going to do it properly and would you want to buy said gun after the local mall ninja played around with it. Plenty of threads about dropping a hammer. On my iPhone too much work, not enough reward.